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Particle Physics with Neutrons

Particle Physics with Neutrons. Hartmut Abele Fundamental Interactions June 22, 2004. Fundamental Interactions. The Standard Model Two parameters: Lambda = g A /g V V ud , CKM matrix Gravity and Quantum Mechanics Observables: The lifetime

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Particle Physics with Neutrons

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  1. Particle Physics with Neutrons Hartmut Abele Fundamental Interactions June 22, 2004

  2. Fundamental Interactions • The Standard Model • Two parameters: • Lambda = gA/gV • Vud, CKM matrix • Gravity and Quantum Mechanics • Observables: • The lifetime • Spin of neutron and decay particles Half a dozen observables • Momenta of decay particles }

  3. Outline • Correlation measurements in beta-decay • beta asymmetry A = 0.1170(13) • neutrino-asymmetry B = 0.983(4) • electron-neutrino angular correlation a = 0.102(5) • triple correlation coefficient D = (0.6 ± 1.0)·10-3 • triple correlation coefficient R: • Axial to vector coupling (correlation A) • gA /gV = 1.2720(18) • Quark mixing and CKM Unitarity (A, lifetime) • Vud = 0.9725(13) • unitarity of CKM-matrix: Vud2 + Vus2 + Vub2 = 1(6.0 ± 2.8)·10-3 • Neutrinos, left/right (A,B correlation) • mass of right-handed boson m(WR) > 281 GeV/c2 (90% c.l.) • left-right mixing angle 0.20 <  < 0.07 (90% c.l.) • New sources of CP violation, (D, R correlation, EDM, this conference) • phase between gA and gV  = (180.08 ± 0.10)0 • Speculation about CPT, (D, R correlation, EDM, this conference)

  4. PROCESSES WITH SAME FEYNMAN DIAGRAM: • Solar cycle p p  D e+ e p p e  D e … • Neutron star formation p e  n e • Primordial element formation n e+  p e'p e  n e n p e e' • Neutrino detectors p e'  n e+ • Neutrino forward-scattering e p e+ n etc. • W, Z-production p p'  W  e e' etc. D.Dubbers

  5. Outline II • Baryon number violation • neutron-antineutron oscillation timen nbar> 0.86·108 s (90% c.l.) • Early Universe • number of neutrino families N= 2.6 ± 0.3 • baryonic matter in universe/crit = (4 ± 1) % • Search for extra dimensions in space time • Gravitational bound quantum states • String theories

  6. Processes that violate baryon number Do neutrons oscillate? n  nbar Baryon-number oscillations B   B? Process allowed in some Grand-Unified Theories • Observable: Antineutron Experimental limit: n nbar > 0.86·108 s (90% c.l.) Limit on neutron oscillations probes 105 GeV range D.Dubbers

  7. A Neutron Spin Electron B Neutrino C Proton Correlation measurements in -decay Observables in neutron decay: Lifetime  Spin Momenta of decay particles

  8. Transition probability Triple correlation bn correlation triple correlation b asymmetry n asymmetry SM: 0 11% -11% 97% SM: 0

  9. Particles And Fields matrix for d-u transition: hadron and lepton currents: vector- and axial vector currents: Lagrange function for neutron decay:

  10. Neutron Spin A A Neutron Spin Electron Electron Coefficient A W(J)={1+v/cPAcos(J)} CoefficientAand lifetime t determineVudandl = gA/gV No coincidences !

  11. Spectrometer Magnetic field Polarizer Spin flipper Cross section neutron beam

  12. A fit • final result: • A = -0.1189(7) • l = -1.2739(19) PRL 88 211801 (2002) Aexp = A v/c Pf Vud=0.9717(13) (4:)(12:A)(4:theory) Dissertation: J. Reich

  13. u e u u u d u d d W Vud d Quark Mixing and CKM Unitarity • Standard Model: • quark-mixing should be 'zero-sum game': • quark mixing = pure rotation in flavor space • i.e. CKM quark mixing matrix should be unitary • Vud from • Nuclear beta decay Vud=0.9740(5), 2.3 sigma • Pi beta decay Vud=0.9717(56) • Neutron beta decay, 2.7 sigma • High energy physics assuming unitarity CKM Matrix

  14. Free Parameters, Standard Model Ft-values Neutron Deviation from unitarity Visible in the “raw” data! hep-ph/0312124 hep-ph/0312150 Vud=0.9717(13) (4:)(12:A)(4:theory)

  15. Conclusion 2002 • Nuclear beta-decay dominated by theoretical errors = 0.0032  0.0014 • Restoration of unitarity: 2.3 sigma shift • Neutron beta decay dominated by experimental errors = 0.0076  0.0028 • Restoration of unitarity: would require a 3 sigma shift in A • a 8 sigma shift in lifetime • radiative corrections are 8 sigma wrong • K decays: 3 sigma shift to explain nuclear beta decay, or 8 sigma shift to explain neutron results

  16. Free Parameters, Standard Model, 2004 Ft-values Neutron Deviation from unitarity Visible in the “raw” data! hep-ph/0312124 hep-ph/0312150 Vud=0.9717(13) (4:)(12:A)(4:theory)

  17. Neutron lifetime t NIST: Mampe et al., PRL 63 593 (1989) Huffmann et al., Nature Munich: ri = 10 cm Ra = 30 cm h = 60 cm

  18. We want • More neutrons • No corrections to raw data • 100% polarization • No background The new A measurement • A new beam • The ‘ballistic’ super-mirror cold-neutron guide H113 • H. Haese et al., Nucl. Instr. Meth. A485, 453 (2002) • New Polarizers • New Geometry for Beam polarization • T. Soldner: A perfectly polarized neutron beam • New analyzer with He cells

  19. Polarization efficiency

  20. Neutron Spin Proton Electron Neutrino Neutron Spin Electron Neutrino Proton Coefficient B Two Techinques Our method: Electron proton coincidence

  21. Proton detector Proton C foil Scintillator • Proton detection: • Measure electron energy • Wait for proton • Convert proton into • electron signal

  22. Proton “electron” spectrum Dissertation: J. Reich

  23. Neutron Spin Proton Electron Neutrino Neutron Spin Electron Neutrino Proton Same hemisphere

  24. B Detector 1 Detector 2 Correction [%] Error [%] Correction [%] Error [%] Polarization & Flip Efficiency (1.5) 0.5 (1.8) 0.5 Statistics 0.8 0.8 Accidental coincidences (3.0) 0.5 (3.5) 0.6 Additional Stop pulses -0.8 0.4 -0.9 0.5 Gain 0.01 0.01 Offset 0.03 0.05 Edge effect (-0.1) 0.05 (-0.1) 0.05 Electro magnetic mirror (0.5) 0.05 (0.5) 0.05 Grid effect (-0.05) 0.05 (-0.05) 0.05 Backscattering Coefficient A 0.03 0.03 Coefficient a 0.06 0.06 Sum -0.8 1.15 -0.9 1.4 Results: B = 0.967±0.012 and C=-0.238 ±0.011Dissertation Kreuz 2004 BPDG = 0.983±0.004 and Ctheory=-0.239

  25. Angular correlations in neutron decay Mainz, Munich • New developments: hep-ph/0312124 CKM-Workshop, Sep. 2002, PMSN-Workshop, NIST 2004 • “little” a: aSpect, Mainz, Munich,2004 • “little” a: Kurchatov Inst., NIST • “Big” A,B,C: HD, 2004 • “Big A + B”: Gatchina • “Big” A: LANL,... • “Big” R: PSI, ongoing • “Big” D: emiT, • “Big” D: Trine, 2003 • “Big” A: HD, 2005 LANSL 135° Geometry: emiT 2000 TRINE 2000

  26. CP and Time Reversal Violation Standard Model Left-right symmetric From CKM phase: D10-12 From d199Hg: D< 10 -4 …10 -5 Exotic fermions Leptoquarks • GUTs • some SuSy models • some superstring models • some composite models • e.g. SU(2)RU(1)L • in some GUTs From d199Hg: D< 10 -4 …10 -5 D limits phases in LQ couplings! P. Herczeg, Prog. Part. Nucl. Phys. 46 (2001) 413. Torsten Soldner: CKM Workshop

  27. Searches for electric dipole moment Why has so much matter survived the big bang? What is the origin of time reversal violation? • CPT = 1: • CP-violation  T-violation • THIS CONFERENCE

  28. FRM2 2004 • Cold neutrons at the FRM II • equivalent to existing source at the ILL • UCN source at the FRM II • 2 orders of magnitude higher density at FRM

  29. PSI, UCN Source, this workshop F overall = 100

  30. INPUT: NEUTRON BEAM CONSTANTS OUTPUT: NEUTRON RATES The ‘ballistic’ super-mirror cold-neutron guide H113 H. Haese et al., Nucl. Instr. Meth. A485, 453 (2002) capture flux Φ 1,4 E+10 cm-2 s-1 intensity I0=ΦA 1,9 E+12 s-1 beam area A 120 cm2 densityρ=Φ/v 1,6 E+05cm-3 mean velocity v 1000ms-1 no. of neutrons per beam length N/l=ρA=I0/v 1,9 E+09m-1 neutr. lifetimet 885 s neutron decay rate/beam length n/l = I0/v/τ 2,2 E+06sec-1 m-1

  31. The New PERKEO proton or electron detector simulated electron trajectories neutron cloud detector proton or electron detector ~2m, 150mT beam stop velocity selector neutron beam chopper decay volume Dubbers, Märkisch, H.A.

  32. The future with the New Perkeo

  33. This work was done by ... • University of Heidelberg • M. Astruc Hoffmann Stefan Baeßler • Dirk Dubbers Uta Peschke • Jürgen Reich H.A. • Ulrich Mayer Daniela Mund • Christian Plonka Christian Vogel H.A. • Bernhard Brand Michael Kreuz • Daniela Mund Markus Brehm • Marc Schumann Jochen Krempel H.A. • Michael Kreuz Stefan Baeßler • Bastian Märkisch • Bastian Märkisch, Dirk Dubbers, Marc Schumann, H.A. • Institut Laue-Langevin • Torsten Soldner, Alexander Petoukhov • GSI, TUM • Mayer-Komor, Kindler • Mainz • Stefan Baeßler, Ferenc Glück, A: B: A: New PERKEO:

  34. Gravity on a Micronand Limits on Large Extra Dimensions • Galilei • Object: Neutron • Fall height: ~ 50 mm Quantum aspect

  35. WKB vs. Analytical perturbative

  36. Effective potential close above the mirror F z

  37. Limits for alpha and lambda a 1014 1013 1012 100 10 1 l m H. A. et al., Lecture Notes in Physics, Springer, 2003

  38. The gravity work has been done by ... • ILL, Grenoble: V. Nesvizhevsky, A. Petukhov, H. Boerner • Gatchina, St. Petersburg A. Gagarsky, G. Petrov, S. Soloviev • Mainz University S. Baeßler • DESY A. Westphal, • Heidelberg University: G. Divkovic, N. Haverkamp, D. Mund, S. Nahrwold, F. Rueß, T. Stöferle, HA • CERN ISN JINR B. van der Vyver K. Protasov, Yu. Voronin Strelkov

  39. Summary: Galileo in Quantumland • Good limits for • non-Newtonian interaction • between 1mm and 5mm • Limits are comparable to other • Limits, Complementary • Yukawa forces modify Airyfunction • And change energy of the state

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